Drill chuck



Feb, 21, 119% c. w. BRAQKER DRILL CHUCK 2 Sheets-Sheet 1 Filed Feb. 18, 1947 Feb. 21, 1950 c. w. BRAcKER DRILL CHUCK Filed Feb. 18, 1947 v 2 Sheets-Sheet 2 5. 4% dilly/a Patented Feb. 21, 1950 UNITED STATES PATENT OFFICE Application February 18, 1947, Serial No. 729,327 In Switzerland December 21, 1945 This invention relates to drill chucks, and particularly to, a, .novelmechanism to actuate the drill holding members.

A main object of my invention is to. provide for adrill chuckrof; compact construction adapted for use withv drills varying. over a wide range in. diameters.

Another object of this invention is toincrease the efiiciency of the clamping mechanism and to adapt said mechanism for. rapid exchange of the drills, either at standstill or while the machine is running.

Another object of my invention is to provide a drill chuck without any projecting parts such as teeth, 'whereby accidents resulting from such projecting, parts. are prevented.

Still another object of thev present invention, is. to. provide a drill chuck. maintaining throughout its operation. a high standard of. precision.

I attain this and related objects by a. drill chuck comprising: a drill chuck head, drill holding members and a rotatable shell housing, resilient means urging the drill holding membersoutward in radial direction to a. position corresponding. to the maximum range of the drill chuck, and other resilient means urging. the rotatable shell type housing to rotate in a direction corresponding to the minimum, drill chuck range; to guide the drill holding members, at lea-st one other guide disk frictionally coupled to the shell housing for intermittently rotating with said shell-housing. the two sets of disks guiding the drill holding members from a minimum to a maximum drill size shaft range, whereby the guide disks coupled frictionally to the rotatable.

shell. housin guide the drill holding. members from the minimum range to an intermediate position of the total range, and the other guide disks from said intermediate position to the maximum range of the drill chuck, operable by rotating the shell-housing in a direction opposing said other resilient means.

Other details will be apparent from the description of the: device illustrated in theaccompanying drawings, in which is:

Figure 1 a longitudinal sectional elevation of. a drill chuck according to this invention,

Figure 2 a section on the line A--A of Figure 1,

Figure. 3- a longitudinal sectional elevation showing the drill chuck in a different position from that shown in Figure 1, also showing at the lower half a modified constructional form from that shown in Figure 1,

Figure 4 a section approximately an the line B--B of Figure 3 showing the clamping members 8 Claims. (Cl. 2 7972);

in a: position indicating the minimum range of the drilllchuck,

Figure 5 a similar section as shown in Figure 4 showing drill holding clamping members, in, a different position,

Figure 6- a similar section as shown in Figure 4 showing a position ofthe clamping members, indicating the maximumrange of the drill chuck,

Figure 7 a detail seen from the front of the drill chuck.

Figur 8 a detail similar to that shown in Figure '7 in another phase of the drill holding members,

Figure 9' a detail of. a clamping member,

Figure 10 a clamping member in another position; from: that shown inFigure 9.

The: Figures 11, 12- and 13v are. diagrammatic, views referring to the actuating. mechanism for the clamping members showing the guide disks in. straight laid out position, their circumference being represented as the straight base-line, in three different positionsof the clamping members.

Referring to Figure the centrall located member I referred to as the chuck head is provided with a bore 2, engaging in any well' known manner the machine shaft 3.

The forward end of the-drill chuck head I is mil-led. and boredtoprovide forradially disposed slots such as indicated by the numerals 4a, 4b and, 4c for'the. clamping or drill holding members of round section in the: form of rollers l. These rollers are movably disposed in the slots ta, 4?) and 4c and are provided with knurled or milled surfaces effecting thereby a firm grip on the shaft of; the drill.

The rollers 4: are independent from each other and are provided at the forward end with extensions 6;v which serve as mountings for plates 1, 8 and 9. These? plates are identically formed and follow the movement. in radial direction of the clamps 4; specific positions of these plates are shown in the Figures '7 and 8.

The plates 1, 8 and 9- are longitudinally displaced so as to clear each other when in a position shown in Figure 8. The purpose of these plates is to prevent the waste-materialv from the. boring, to enter the drill chuck, in that a very small space between these plates and a cover plate 22 is provided.

The clamps 4 are provided with a. flared blind bore-hole In as shown, In. this bore til one end oi spring H- is firmly secured in the cylindric end-part of this hole, the other endis rigidly connected in a hole of the chuck head.

Between. the head l= andthe shell typev housing,

I a spiral spring I9 is disposed and. holds with one end the shell type housing I5 and with the other end the chuck head I. This spring serves to rotatably displace the drill chuck head and the shell-housing in relation to each other, so as to keep the clamping members in the closed position unless interfered with, in this respect, from the outside. A pin seated in the drill chuck head I provides for a stop limiting the movement of the shell I5 in that the stop abuts the ends of a groove in the shell-housing.

The clamp rollers 4 are controlled by mechanism consisting of' members I2, I3 and I4 shaped as guide-disks for the clamping members 4, in that they are provided with suitably curved in-. side surfaces, guiding the resilient radial movements of the clamps 4 while engaging the shaft of a drill tool under the pressure of springlS after the shell has been rotated in direction opposite the pressure of said spring. 1

The guide disks I2, I3 and the guide disk I4 provide together the uiding surfaces, controlling the clamp rollers 4.

The guiding or controlling surfaces of the guide rings I2 and I3 are identical in shape and are by means of a pin I 6 firmly or integrally secured to the rotatable shell I5.

The rotatable shell I5 is longitudinally fixed by means of a cap nut IIa preventing displacement in axial direction of the guide disks I2 and I3, which are rigidly connected to the shell I5.

The guide disk I4 is rotatably disposed within the shell I-5, between the uide disks I2 and I3, rotating with the shell I5 by frictional coupling, but may also be held fixed in a firm position while the shell I5 and the guide disks I2 and I3 are rotated. The mechanism pertaining to this function consists according the accompanying drawings in a circumferential notch 11 cooperating with the pin I6. Relative movements between the guide disk I4 and the guide disks I2 and I3 is thereby limited according the angular length of the notch I'I preferably to an angular movement of 90.

. The controlling members I2, I3 and I4 may also consist of guide disks as shown in the lower part of Figure 3. In this case disks I4 for limited movements are arranged between disks I2 for unlimited movement. 1

The radial movement of the clampin rollers 4, from their minimum drill holding range shown in Figure 4, to the drill holding range shown in Figure 5, is controlled by the guide disk I4 alone. From there on the guide disks I2 and I3 cooperate equally and alone with the clamping rollers 4. During the latter operation, the movement of guide disk I4 is interfered with by the abutments 2I and the guide rollers 4, see also Figure 12. From this instant on the guide disks I2 and I3 may be moved on, alone, in that the pin I6 travels in the notch ll of the guide disk I4, from one end to the other end of the notch. In other words when rotating the shell I5 in the direction in which the spiral spring I9 is wound up, the clamp rollers 4 move in the grooves 4a, 4b and 4c due to the springs II which urge the clamp rollers in radial direction towards the outside against the guide surface of disk I4. The control members I2, I3 and I4 rotate simultaneously with the shell I5 until the clamping rollers 4 abut the elevated position 2| of the guide disk i4. Beginning at this instant, the rollers 4 glide on the controlling surface of the guide disks I2 and I3 until the range of greatest magnitude is attained as shown in Figure 6 and diagrammatically shown in Figure 11. During this period, the pin I6 moved between the two abutments I8 of the notch I! and the clamping rollers 4 are guided by the control surfaces of the guide disks I2, I3 and are located in a rest-position 23 0f the guide disk I4.

The operation of the two control surfaces of the disks I2, I3 and the control-surface of the disk I4 is illustrated diagrammatically in the Figures 11, 12 and 13.

The open position of the drill chuck is shown in the Figures 6 and 11. Figures 5 and 12 show an intermediate position of the drill chuck range correspondin to the end of the active movement of the control or guide disk I4. The control surfaces of the rings I2 and I3 in the position shown in Figure 11 have been displaced from the position shown in Figure 12 in that they have been further rotatedand the disk I4 due to its collision with abutment 2| has been held fixed whereby the pin I6 travelled in the notch II.

The illustration of Figure 13 corresponds to the illustration shown in Figure 4 and shows the clamping rollers 4 almost on the highest elevation of cam 2I of the control ring I4, enabling them to grip'a tool of small diameter.

I claim:

1. A drill chuck comprising a chuck head, drill holding members and a rotatable shell housing, resilient means urging the drill holding members in radial direction to a position corresponding to the maximum range of the drill chuck, and other resilient means urging the rotatable shell type housing to rotate in a direction corresponding ,to the minimum drill chuck range, a guide disk rigidly connected to the shell housing to guide the drill holding members, a second guide disk frictionally coupled to the shell housing for intermittently rotating with said shell-housing, said disks guiding the drill holding members from a minimum to a maximum drill size shaft range, whereby said guide disk coupled frictionally to the rotatable shell-housing guides the drill holding members from the minimum range to an intermediate position of the total range, and the other guide disk from said intermediate position to the maximum range of the drill chuck, said disks being operable by rotating the shell-housing in a direction opposing said other resilient means.

2. A drill chuck as set forth in claim 1, wherein said frictionally coupled guide disk has an elevated surface abutting said drill holding members rendering said frictional coupling ineffective and said first mentioned guide disk effective to guide said drill holding members to their maximum range and means rotating said first mentioned guide disk while the frictionally coupled guide disk is held fixed by said drill holding members.

3. A drill chuck as set forth in claim 2, in which said means rotating said first mentioned guide disk, comprises a circumferential notch in said frictionally coupled guide disk, and a pin travelling in said notch securing said first mentioned guide disk to the shell-housing.

4. A drill chuck as set forth in claim 3 wherein two rigidly coupled guide disks are provided having identical guiding faces and said second guide disk is located therebetween.

5. A drill chuck as set forth in claim 1 wherein a cap nut on said shell-housing cooperating 6. A drill chuck as set forth in claim 1 wherei in the frictionally coupled guide disk is provided REFERENCES CITED with a guiding urface having rest-positions for The following references are of record in the said drill holding members. file Of this p n 7. A drill chuck as set forth in claim 1, where- 5 in said rigidly coupled guide disk is integral with UNITED STATES PATENTS said shell-housing. Number Name Date 8. A drill chuck as set forth in claim 1, in 97 ,345 Dalton Oct. 18, 1910 which a. plurality of guide disks are provided 2,063,344 Schneider c- 1936 contiguous to a plurality of rigidly coupled disks, 1 2,311, 58 Sjogren Feb. 16, 1943 Said latter disks being in the dd numbered ,380,648 Hite July 31, 1945 positions and said frictionally coupled disks in the even numbered positions.

CARL WALTER BRACKER. 

